The present invention relates to a turntable device for, e.g., an optical disk drive and, more particularly, to a turntable device which is driven by a spindle motor while carrying a disk-like recording medium implemented as an optical disk thereon.
An optical disk drive for driving an optical disk which is a removable hubless recording medium is conventional and includes a turntable and an optical head. To allow the optical axis of the head to accurately track the disk, it is preferable that the eccentricity of the disk be as small as possible. Specifically, the disk is loaded on the turntable with its center hole coupled over a projection protruding from the turntable and having the same diameter as the hole. When the projection is cylindrical, any clearance between the projection and the edge of the hole would bring about eccentricity. However, such a clearance is necessary for the disk to be smoothly loaded and unloaded from the turntable. Moreover, the hole of the disk has some tolerance for production reasons, so that the above clearance depends on the disk so long as the projection is cylindrical.
While various approaches have heretofore been proposed for obviating the eccentricity of an optical disk, none of them is capable of fully obviating it. In addition, conventional turntable devices cannot be reduced in size, particularly thickness,
Technologies relating to the present invention are taught in, e.g., Japanese Patent Laid-Open Publication Nos. 60-124056, 60-124057, 60-124058, 60-187966 and 63-187452, Japanese Utility Model Laid-Open Publication No. 63-195654, Japanese Patent Laid-Open Publication Nos. 64-23456 and 1-185869, and Japanese Utility Model Laid-Open Publication Nos. 2-50852 and 2-128244.